Dorothy Hodgkin and C. H. (Harry) Carlisle publish the first three-dimensional molecular structure of a steroid, cholesteryl iodide. In January, Hodgkin also discovers the structure of penicillin, not published until 1949.
November - Assembly of the world's first general purpose electronic computer, the Electronic Numerical Integrator Analyzer and Computer (ENIAC), is completed in the United States, covering 1,800 square feet (170 m2) of floor space, and the first set of calculations is run on it.
August 11 - The Smyth Report is released by the United States government, informing the public of the basics of nuclear fission and its military and civilian applications, and emphasizing the role played by physics in the development of the atomic bomb.
ArgentinephysicistErnesto Sabato publishes Uno y el Universo ("One and the Universe"), a collection of essays criticizing the apparent moral neutrality of science and warning of dehumanization in technological societies.
^Angier, R. B.; Boothe, J. H.; Hutchings, B. L.; Mowat, J. H.; Semb, J.; Stokstad, E. L. R.; Subbarow, Y.; Waller, C. W.; Cosulich, D. B.; Fahrenbach, M. J.; Hultquist, M. E.; Kuh, E.; Northey, E. H.; Seeger, D. R.; Sickels, J. P.; Smith Jr, J. M. (1945). "Synthesis of a Compound Identical with the L. Casei Factor Isolated from Liver". Science. 102 (2644): 227–228. Bibcode:1945Sci...102..227A. PMID17778509. doi:10.1126/science.102.2644.227.